The bold promise of viral antibody testing is not yet met

Washington-at the height of Coronavirus Blockade, president Donald Trump And his top health The advisors trumpeted a new test to help Americans regain their lives. The test tells you if you are already infected with the virus and are protected from getting the virus again.

Their arrival will help “return Americans to work” by showing people who may have “wonderful, beautiful immunity,” Trump said.

A few months later, the United States is flooded with tests, but the bold prediction of its usefulness has yet to come true.

“There was definitely a lot of hopeful thought that there would be a magic test that would save us all, but it’s not there yet,” said Dr. Jennifer Lakeman of the Institute of Public Health in New York City. ..

This test tests the blood for antibodies that the body makes to prevent infection. Scientists are still working to figure out how well antibodies against coronavirus can protect someone from other infections, or how long that protection will last. Some early studies suggested a rapid decline in immunity. The study published last week is more promising, suggesting that the antibody persists for at least 4 months after diagnosis and does not disappear immediately.

At the moment, the Centers for Disease Control and the American Medical Association have clearly warned that decisions should not be made about returning workers to offices or returning students to school using antibody tests, but Some laboratories recommend their use. The CDC recommends that everyone (including those who recover from the disease) take precautions to prevent the spread of the virus.

Experts say that expecting answers to key immune questions early in the outbreak was probably unrealistic. Mark Jenkins of the University of Minnesota said these questions have traditionally been answered only through long-term animal or human studies.

The National Institutes of Health and universities are doing some of this work, but much of it has retreated to the rapid development of vaccines during the pandemic.

“Everyone is impatient and understands why,” Jenkins said. About immunity “But there is no easy way to this knowledge.”

Antibody tests differ from the standard nasal swab test, which diagnoses active infections. Instead, they use blood samples or fingersticks of blood to look for signs of past infections, whether they are sick or have no symptoms at all. Based on other viruses, experts expect that viruses with coronavirus antibodies will be immune, at least in part for months, if not more.

Dr. Anthony Fauci and other members of the White House Task Force earlier said that “protection with antibodies” is a “reasonable premise”, but added no evidence.

To get the proof, scientists first perform experiments on animals. A human trial will follow, which may take longer. Researchers track infected people and develop antibodies to see if they get reinfected. These antibodies are measured to determine the level needed for immunity.

Jenkins and colleagues said that it is entirely possible that an effective vaccine will arrive before the coronavirus antibody study is complete, helping answer some key questions. Vaccines boost the production of antibodies and many coronavirus vaccines are currently being tested worldwide.

On the other hand, experts say that antibody testing is useful in two ways: Extensive research in the general population to see how far the coronavirus has spread, and screening of people who may donate antibody-rich plasma Experimental treatment of COVID-19.

However, according to Nielsen, these applications attracted 8 to 10 million cable TV viewers daily, not the focus of the White House briefing last spring. A spokeswoman for the White House Coronavirus Headquarters did not provide a response to the request for comment.

The Food and Drug Administration chose the “flood zone” strategy because of the high demand expected. This allows you to start over 170 tests with little monitoring.

At the same time, Trump emphasized that his administration’s “great breakthroughs” would bring antibody testing to the market, some authorities had raised concerns. A report by the European government, which had to drop millions of false tests, alerted.

“We will be very cautious when you tell you that you are more likely to be immune from illness…the test really said it,” Admiral Brett Giroir, Administration. “The emperor of the test,” said.

The FDA withdrew its loose policy on antibody testing in May and called on companies to start submitting accuracy data. To date, the FDA has authorized around 40 and dozens more are waiting for review.

Despite regulatory precautions, some testing companies continue to advertise their tests to workers and others. Large laboratories, including LabCorp and Quest, offer tests to employers along with other services such as temperature checking.

Quest spokesperson Kimberly Gorode said in a statement: “I know the CDC’s guidance, so using antibody testing as part of a holistic approach to bring employees back into the office. I recommend.”

LabCorp said in a statement: “As our knowledge grows, it may be beneficial to have access to this information.”

At a New York City test site in April, Somos doctors, a non-profit organization serving the low-income community, admitted that those who tested positive for antibodies were “not 100% nothing” Even so, he said that he could safely return to work. In a recent interview, the group’s founder, Dr. Ramon Taraj, defended the test. He said the workers would have been expected to come back anyway. He said the antibody test simply provided an “additional layer of protection.”

CDC and state public health Government agencies continue to use antibody tests to track the spread of the virus in the United States. So far, most of the areas surveyed have less than 5% of the population with antibodies. This is well below the level most experts think is necessary for herd immunity to coronaviruses, underscoring the need for vaccines.

At this time, Jenkins does not recommend spending money on antibody tests unless the doctor recommends it.

“Even the research community can’t really tell you what the results mean,” Jenkins said.

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This story has been updated to correct the names of New York City Institute of Public Health personnel. Jennifer, not Allison. It also corrects the spelling of Marc Jenkin’s name. It’s a mark, not a mark.

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Follow Matthew Perone on Twitter: @ AP—FDAwriter

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New York AP Video Journalist Marshall Ritzel contributed to this report

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The Associated Press Health Sciences Department is supported by the Science Education Department of the Howard Hughes Medical Institute. AP is solely responsible for all content.